---
title: "CSVDocumentSplitter"
id: csvdocumentsplitter
slug: "/csvdocumentsplitter"
description: "`CSVDocumentSplitter` divides CSV documents into smaller sub-tables based on split arguments. This is useful for handling structured data that contains multiple tables, improving data processing efficiency and retrieval."
---

# CSVDocumentSplitter

`CSVDocumentSplitter` divides CSV documents into smaller sub-tables based on split arguments. This is useful for handling structured data that contains multiple tables, improving data processing efficiency and retrieval.

<div className="key-value-table">

|                                        |                                                                                                                                                  |
| :------------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------- |
| **Most common position in a pipeline** | In indexing pipelines after [Converters](../converters.mdx) , before [CSVDocumentCleaner](csvdocumentcleaner.mdx) |
| **Mandatory run variables**            | `documents`: A list of documents with CSV-formatted content                                                                                      |
| **Output variables**                   | `documents`: A list of documents, each containing a sub-table extracted from the original CSV file                                               |
| **API reference**                      | [PreProcessors](/reference/preprocessors-api)                                                                                                           |
| **GitHub link**                        | https://github.com/deepset-ai/haystack/blob/main/haystack/components/preprocessors/csv_document_splitter.py                                    |

</div>

## Overview

`CSVDocumentSplitter` expects a list of documents containing CSV-formatted content and returns a list of new `Document` objects, each representing a sub-table extracted from the original document.

There are two modes of operation for the splitter:

1. `threshold` (Default): Identifies empty rows or columns exceeding a given threshold and splits the document accordingly.
2. `row-wise`: Splits each row into a separate document, treating each as an independent sub-table.

The splitting process follows these rules:

1. **Row-Based Splitting**: If `row_split_threshold` is set, consecutive empty rows equalling or exceeding this threshold trigger a split.
2. **Column-Based Splitting**: If `column_split_threshold` is set, consecutive empty columns equalling or exceeding this threshold trigger a split.
3. **Recursive Splitting**: If both thresholds are provided, `CSVDocumentSplitter` first splits by rows and then by columns. If more empty rows are detected, the splitting process is called again. This ensures that sub-tables are fully separated.

Each extracted sub-table retains metadata from the original document and includes additional fields:

- `source_id`: The ID of the original document
- `row_idx_start`: The starting row index of the sub-table in the original document
- `col_idx_start`: The starting column index of the sub-table in the original document
- `split_id`: The sequential ID of the split within the document

This component is especially useful for document processing pipelines that require structured data to be extracted and stored efficiently.

### Supported Document Stores

`CSVDocumentSplitter` is compatible with the following Document Stores:

- [AstraDocumentStore](../../document-stores/astradocumentstore.mdx)
- [ChromaDocumentStore](../../document-stores/chromadocumentstore.mdx)
- [ElasticsearchDocumentStore](../../document-stores/elasticsearch-document-store.mdx)
- [OpenSearchDocumentStore](../../document-stores/opensearch-document-store.mdx)
- [PgvectorDocumentStore](../../document-stores/pgvectordocumentstore.mdx)
- [PineconeDocumentStore](../../document-stores/pinecone-document-store.mdx)
- [QdrantDocumentStore](../../document-stores/qdrant-document-store.mdx)
- [WeaviateDocumentStore](../../document-stores/weaviatedocumentstore.mdx)
- [MilvusDocumentStore](https://haystack.deepset.ai/integrations/milvus-document-store)
- [Neo4jDocumentStore](https://haystack.deepset.ai/integrations/neo4j-document-store)

## Usage

### On its own

You can use `CSVDocumentSplitter` outside of a pipeline to process CSV documents directly:

```python
from haystack import Document
from haystack.components.preprocessors import CSVDocumentSplitter

splitter = CSVDocumentSplitter(row_split_threshold=1, column_split_threshold=1)

doc = Document(
    content="""ID,LeftVal,,,RightVal,Extra
1,Hello,,,World,Joined
2,StillLeft,,,StillRight,Bridge
,,,,,
A,B,,,C,D
E,F,,,G,H
"""
)
split_result = splitter.run([doc])
print(split_result["documents"])  # List of split tables as Documents
```

### In a pipeline

Here's how you can integrate `CSVDocumentSplitter` into a Haystack indexing pipeline:

```python
from haystack import Pipeline, Document
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.components.converters.csv import CSVToDocument
from haystack.components.preprocessors import CSVDocumentSplitter
from haystack.components.preprocessors import CSVDocumentCleaner
from haystack.components.writers import DocumentWriter

## Initialize components
document_store = InMemoryDocumentStore()
p = Pipeline()
p.add_component(instance=CSVToDocument(), name="csv_file_converter")
p.add_component(instance=CSVDocumentSplitter(), name="splitter")
p.add_component(instance=CSVDocumentCleaner(), name="cleaner")
p.add_component(instance=DocumentWriter(document_store=document_store), name="writer")

## Connect components
p.connect("csv_file_converter.documents", "splitter.documents")
p.connect("splitter.documents", "cleaner.documents")
p.connect("cleaner.documents", "writer.documents")

## Run pipeline
p.run({"csv_file_converter": {"sources": ["path/to/your/file.csv"]}})
```

This pipeline extracts CSV content, splits it into structured sub-tables, cleans the CSV documents by removing empty rows and columns, and stores the resulting documents in the Document Store for further retrieval and processing.
